Motor-control system



A. L. HARVEY.

MOTOR CONTROL SYSTEM.

APPLICATION man JULY 1,1920.

Patented May 2,1922.

INVENTOR fl/berIL. Harvey.

ATTORNEY UNITED STATES PATENT OFFICE.

ALBERT L. HARVEY, OI WILKINSBURG, PENNSYLVANIA, ASBIGNOB 1'0 WESTING. HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION 01' PENN vague.

MOTOR-CONTROL SYSTEM.

Specification of Letters ratent. P t t M 2, 1922.

Application filed July 7, 1920. Serial No. 394,438.

To all whom it may concern:

Be it known that I, ALBERT L. HARVEY, a

citizen of the United States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Motor-Control Systems, of which the following 1s a specification. My invention relates to motor-control systems and it has particular relat1on to such systems as are employed in connect on with the operation of a motor by a plurality of controllers or switching devices that are separated from each other by relatively great distances.

My invention has for its object to pro vide a relatively simple and convenient means of control for a motor-operated gun lathe of relatively great length having a plurality of carriages each of which has a master controller mounted thereon; the master controllers being arranged in such order or sequence that the operation of each controller is dependent upon the electrical connections established by other controllers that are located prior in the order or sequence and independent of the controllers subse-v quent to it in the sequence.

Briefly speaking, my invention consists in providing a plurality ofmaster controllers that may be selectively adapted for operating a motor, each controller being mounted upon a separate carriage. All but one of the controllers are made subject to the op erationof other master controllers that are placed on the other carriages. One or more carriages may be usedat one time for turning a gun, as hereinafter more fully set forth. However, the most skilled wor an determines whether the motor shall operate and, if so, in whichdirection. If he leaves the first controller, which is preferably placed on the carriage nearest the head stock of the lathe, in an off position, the next workman ma control the operation of the lathe and, li ewise, other workmen, in a predetermined order, may also control its operation. 1

For abetter understanding of my 1nvention, reference may be made to the accompanying drawing, which is a diagrammatic view of a control system embodying my 1nvention.

Line conductors 1 and 2, which may be connected to any suitable source of energy supply current to an electric motor having. an armature 3, a shunt field-magnet windmg 4; and a series field-magnet winding 5. A starting resistor 7 is connected in the armature circuit of the motordurin the starting period thereof. ,An adjustab e res1stor 8 is connected in circuit with the shunt field-magnet winding 4. A dynamicbraking resistor 10 is connected in circuit with the motor. armature 3 when the operating circuit of the motor is open.

The "armature circuits of the motor are controlled by two pairs of mechanically interlocked directional or reversing contactors 11 and 12, and 13 and 14, in accordance with a fam liar practice. The respective pairs of reversing contactors are provided with actuating coils 15 and 16. The dynamic-brakmg circuit of the motor is completed by contactors 17 and 18, which are mechanically connected to the respective pairs of directional switches and are maintained in their respective closed positions by series holding coils 20 and 21.

The starting resistor 7 may be shunted by a contactor 22 having an actuating coil 23 that is connected across the terminals of the armature 3, or that may be energized in accordance with any other. suitable method of acceleration.

When the armature reaches a certain speed, the coil 23 1 cieiitly energized by the counter-electrcrncnve force thereof to close the contactor 22, which short-circuits the starting resistor, thus connecting the armature directly to the supply circuit.

A plurality of master controllers 24, 25,. 26 and 27 are mounted upon carriages (not shown) which are s aced relatively great distances apart, and t e controllers are connectedto energize coils 15 and 16 b means of conductors 28 and 29, respective y. The master controller 24 may be assumed to be upon the carriage that isnearest the head stock of the lathe. The controllers are supplied with electrical energy bya'conductor 30, the energization of which is controlled by a loWv0ltage relay 31 having an actuating coil 32 A resistor 33 and a push-button switch 35 are electrically connected to the actuating coil 32.

Each of the controllers 24, 25, 26 and 2 7,v has a forward position a, a central or oil? position 0, areverse mediate positions 6 an In each of the master controllers 24 to 27, inclusive, contact segments 36 and 37 are electrically connected to a relatively long segment 38 by connectors 39 and 40, respectively. Each controller is provided with a plurality of suitably arranged contact fingers 41, 42, 43 and 44. The co-ntact fingers 43 and 44 are electricallv connected only when the contact segments 37 and 38 are in the normal or off position shown in the drawing.

It may be assumed that the various master switches 24 to 27, inclusive, initially occupy their respective illustrated off positions and that line conductors 1 and 2 and the shunt field-magnet winding 4 are electrically energized. By closing push-button switch 35, an electrical circuit is established from positively energized conductors 30, through the movable contact member of the push-button 35. conductor 34, resistor 33, actuating coil 32 and conductor 28 to the negative supply conductor 2. The closing of the relay 31 completes a holding circuit comprising conductors 30 and 30*, movable contact member 31 of the relay, resistor 33, actuating coil 32 and negative conductor 28 The relay 31 will thus remain closed after the push-button switch 35 is opened, until the line conductors 1 and 2 are de-energized.

By the abovedescribed operation, the electrical circuit to the master controllers 24, 25, 26 and 27 are completed. The workmanat controller 24 may operate the motor in a forward direction by moving the controller handle from the off position 0 to the forward position 0;. This movement completes an electrical circuit from the conductor 34 through controller 24 and conductor 50 to the conductor 28-, thereby electrically energizing the actuating coil 15, which closes the forward directional contactors 11 and 12 and opens the dynamic-braking contactor 17. The closing of the forward directional contactors 11 and 12 completes the electrical circuit for the forward operation of the motor which comprises line conductor 1, contactor 11, armature 3, contactor switch 12, starting resistor 7 series fieldmagnet winding 5 and the line conductor 2.

The movement of the controller 24 to position Z), c or (Z, the remaining controllers being in their respective normal or off )0- sitions, breaks the electrical connection etween the conductors 28 and 34 and de-energizes the actuating coil 15, thereby opening directional contactors 11 and 12 and closing dynamic-braking contactor 17 By actuating the controller 24 to the reverse position e, conductors 34 and 29 are electrically connected through the contact segments of the controller and conductor 51, whereby the actuating coil 16 is energized. In this wa the reverse directional contactors 13 and 14 are closed and dynamic-braking contactor 18 is opened. The closing of directional contactors 13 and 14 completes an electrical circuit for the reverse operation of the motor comprising line conductor 1, contactor 13, armature 3, contactor 14, starting resistor 7, series field-magnet winding 5 and line conductor 2.

Reverse movement of the controller 24 from the position 6 breaks the electrical circuit from the conductor 34 to the conductor 29, thus de-energizing the actuating coil 13, and opening reverse directional contactors 13 and 14 and closing the dynamic-braking contactor 18.

The operation of any one of the master controllers 25, 26 and 27 is similar to that described for the controller 24. It is apparent that, unless each of the prior controllers is in its normal or off postion, the circuit through the various continuations 34, 34 34, etc., of the conductor 34 is interrupted; therefore, the movement of any subsequent controller to either a forward, or a reverse position will not connect either the conductor 28 or 29 with the conductor 34.

In this way, the operation ofthe gun lathe by any workman is subject to the electrical condition of the prior controllers under the direction of other workmen.

If the motor be operated by any one of the master controllers 25. 26 or 27, its operation may be stopped by bringing the master controller 24 or any prior controller into either of the intermediate positions F) or (Z, thereby breaking the circuit through the conductor 34. The continued movement of the controller 24 or any prior controller to either the forward position a or the reverse position 6 will cause the motor to operate in accordance with the position thereof regardless of the position of any-subsequent controller.

It is apparent that, so long as the master controllers 24-, 25, 26 and 27 are arranged in the same relation with respect to the electrical conductors 28, 29 and 34, they will operate as described, regardless of whether their relative side-by-side locations correspond to those shown in the drawing.

While I have shown my invention in a preferred form, I do not wish to be restricted to the specific circuit connections, structural details, or arrangement of parts herein set forth, as various modifications thereof may be effected within the spirit and scopeof my invention. I desire, therefore, that onlysuch limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

1. The combination with a dynamo-electric machine, and means for effecting t different types of operation thereof, cl plurality of controlling devices in predet mined electrical arrangement and each having a plurality of positions adapted for ward and a reverse operative mote control of said machine, and means associated with each of said controlling de-I vices whereby any subsequent device is operative only 1 during the period that a prior device occupies a predetermined position. 2. The combination with a d namo-electric..machi'rie, and means for e ectlng two different types of operation thereof, of a plurality o controlling devices in redete-rmined electrical arrangement and a apted for remote control of said machine, and means governed by said devices whereby the operation of each device is respectiveiliy de-- pendent upon certain conditions of di erent numbers of the other devic,e s prior thereto in saidarrangement..

3. The combination. with a l d namo-electric machine, and means-for e ecting two 'di'fierent types of operation thereof, ofa lurality of controlling devices connecte in predetermined sequence and adapted for remote control of said machine, eachhaving an inoperative position and a plurality of operative positions and means governed by each of said devices for rendering all subsequent devices inoperative upon one of said devices prior thereto occupying a predetermined position.

4. The combination with a d name-electric machine, and means for e ecting two difierent types of operation thereof, of a plurality of controlling devices connected in a predetermined sequence and ada ted for remote control of said machine, eac device having an inoperative position and a forosition and means 'for renderingv each device operative only during the period that the other devicesprior theretoin said sequence arein'.

their. respective inoperative positions.

5. The combination with a dynamo-electric machine, and means for effecting two difi'erent types of operation thereof, of 'a' prising a plurality of contact devices gov-- erned by said controlling devices for energizing said controlling devices by connecting them in series. re ation when all prior devices occupy'inoperative positions.

7. The combination with an electric 1110- 'tor and means for efiecting two diflerent vtion of said coils types of operation thereof, of a pluralityof master controllers adapted for remote .control of said motor, each. of said controllers having an inoperative position and a plurality of operative positions, and means whereby the operation of said controllers is respectively dependent upon certain numbers of the other controllers being in inop erative positions.

-. 8. The combination with. an electric. mo-

tor and directional contactors having actuating coils for controlling the operation of said motor, of a plurality ofcontrollers hav ing a plurality of positions adapted for governmg the-energization of said coils, said controllers being in predetermined electrical arrangement, and means associated with ieach controller for r'eventing the energizay any subsequent controller when any prior controller occupiesan operative positlon.

9.- The combination with a d namo-electric machine, and meansfor e ecting two .difierent types of-operation thereof, of a plurality of master controllers arranged in a predetermined sequence for controlling said machine, and means whereby the operation of each controller is dependent upon the position of the prior controllers and independent of the subsequent controllers in said i sequence. I I

10. The combination with an electric motor, a' pair of interlocking contactors corresponding to forward operation of said motor, another pair of contactors corresponding to reverse operation of said motor, and a plurality of coils for actuating said contactors, of a plurality of master controllers arranged in predetermined sequence for controlling the energization ofsaid coils, means comprising a supply circuit for energizing 'said coils, and means associated with each controller for disconnecting all subsequent controllers from said circuit upon' a prior controller being out of its ofi position.

- 11." The combination with an electric motor, directional contactors controllin the forward .and' the reverse operations 0 said motor, of a plurality of master controllers forycontrolling said contactors, each controller having a central off position, operatiye positions at each side of said ofi position corresponding to the direction of operat on of said motorand an intermediate position between each of said 0 erative po- 7 sitions and said ,off position, tli

I e operation of said controllers being dependent upon certain other controllers being in an oil position. r

In testimony whereof, I have hereunto sl glgigcribed my name this 1st day of July rue v .AIlBERT L. ARVEY} j 

